Electrically-connected printing-machine



No. 623,293. Patented Apr. Is, |999.

c. A. suma J. .1. oLALon. ELEGTBICALLY GUNNECTED PRINTING MACHINE.

(Application ined Apr. 20, 1896.) (No Model.) 3 Sheets-Sheetl.

No. 623,293. Patented Apr. la, |899. c. A. SHEA & .1. .1. uLALoR.ELECTRIGALLY CONNECTED PRINTING MACHINE.

(Application med Apr. 20, 1896,) (N o M ode! a sham-sneu 2.

No. 623,293.- Patented Apr. I8, |899.

y C. A. SHEA &. J. ,.I. OLALUR. ELECTHICALLY CDNNECT`ED PRINTINGMACHINE.

(Application led Apr. 20, 1898.) (No Model.) 3 Sheets-Sheet 3.

ET w @Hirten STATES Pa'rnivr Ormea.

CHRISTOPHER A. SHEA, OF MILTON, AND JOHN OLALOR, OF MEDFORD,MASSACHUSETTS.

ELECTRICALLY-CONNECTED PRINTING-MACHINE.

SPECIFICATION forming part of Letters Patent No. 623,293, dated April18, 1899.

Application filed April 20,1896.

To all 'wh/)772, t nifty concern,.-

Be it known that we, CHRISTOPHER A. SHEA, of Milton, in the county ofNorfolk, and JOHN J. OLALOR, of Medford, in the county of.Middlesex,State of Massachusetts, citizens of the United States, have invented anew and Improved Electrically-Oonnected Printing-Machine, of which thefollowing is a full, clear, and exact description, reference being'hadto the accompanying drawings, forming a part of this specification, inexplaining its nature.

Our invention relates to improved apparatus for use withelectrically-connected printing-machines whereby the depression of a keyby the operator of the transmitting-machine will cause the correspondingkey of the receiving-machine to be operated. The devices which have beenin use heretofore for accomplishing this purpose have been objectionablefor several reasons. Some of the systems require several line-wires andthe initial expense is so great as to preclude their use. Others useonly one wire; but these systems depend on the action of synchronousmotors at each end of the line. When these motors get out of step, amisprint results and every letter subsequently struck is misprinted. lnorder to correct this, the machines have to be broughtto unison and theinotorsthus brought back to synchronism. This is often a matterrequiring some time, and nntil it is accomplished the machines areuseless. By our invention we are enabled to do without the synchronousmotors, and thus obviate the likelihood of misprinting.

An important feature of our invention is that all the machines in theline are antomatically brought to unison after the printing of cachletter. The operating paris of the machine start from the same positionof rest or unison-point as each key is depressed, and after the key isreleased the arms are brought to that point again.

\Ve have shown our invention as applied to the Hammond type-writer; butit may be used with any printing-machine which' operates on a similarprinciple.

ln the drawings, Figure lis a diagrammatic representation of ourinvention, showing a transmitting and a receiving type-writer connectedby a line-wire. Only so much of the stanno. 588.2783. (Nomoaetitype-Writers is shown as is necessary to explain the operation of ourinvention. Fig. 2 is a view in section representing the carriage feedand return. Fig. 3 is a detail View to which reference will hehereinafter made. Fig, a shows the manner in which the capital or figurekey -of the receiving-machine is operated.

Fig. l represents two Hammond type-writers connected by a singleline-wire. 'The machines with our invention added are alike, so thateither one may be used as a transmitter or receiver; but for conveniencein description we have represented X as the transmitting-station and Yas the receiving-station.

P is a key fulcrumed at F, which when struck with the finger by theoperator at station X raises a rod R, which protrnd es through the holeh. At the same time the key raises an arm A, which is fastened to theshaft. S, to the other end of which is secured a drivingarm D, carryingat its end a fork E. Vh'en the driving-arm is moved forward by theraising of arm A, the fork engages with a pin p, which is attached tothe type-shuttleT, having on its periphery the type. This movementadvances the type-shuttle until it strikes the shuttle-arm M, which,being movable, is carried along with it, the front end moving to theright until it strikes the rod R. which has Y been raised by the backend ot' the key P. This stops the shuttle-arm and with it thetype-shuttle and presents to the hammer H the letter P. By this timethe' key P has raised another arm N, which at its' back carries aprojectionn. This projection moves downward when the arm N is raised andin doing so strikes the back end of the pawl n', forcing it down. Thefront end of the pawl n rises, engages, and moves the ratchet O', whichrotates one step, being stopped after that by the front end ot' thepawla', which engages with it on rising. The ratchet-wheel moves on the pawln4, the purpose of which is to prevent by its engagement with the teethof the ratchet the backward movement therespring which drives the hammerforward, printing the letter P on the paper. The key P is then releasedby the operator and falls back to its normal position. The ham- Therotation ofthe ratchet O releases a IOL) ` mer ies back, the spring srestores the arm A to its normal position, and the driving-arm D, thetype-shuttle T, the shuttle-arm M, and the rod R are restored to theirnormal positions and all parts of the machine resume the positions shownin Fig. l. When the next key is depressed, the same movements occur, andthe letter corresponding to that key is printed on the paper. Thesemovements belong to the Hammond type-writer and are only described inorder to show how the electrical apparatus is adaptedto them.

lVhen the shuttle-arm M is moved by the 'driving-arm D over toward therod that has been raised by the depression of the key, it moves over andmakes contact with a commutator C', which is divided into segments, eachsuccessive segment being connected to an opposite polarity of current.

G G' are positive and negative dynamos furnishing the current. Vhen thekey P has been depressed by the operator, the shuttlearm is moved overto the rod of that key and comes to a stop when it strikes it. If thekey were the fifteen th key, the shuttle-arm would move over fourteensegments of the commutator and come to rest on the fifteenth, sending tothe line and the station Y fifteen alternations of current. The line isconnected from the shuttle-arm to the post CL and thence to thetwo-point switch a', which is turned to the left-hand con tact at thetransmitting-station X when it is desired to print to station Y, asshown in Fig. l.

It will be noticed from the foregoing description that the shuttle-arm Mreturns to its original position or unison-point on the segment m of thecommutator C after each key is released and starts from that point whenthe next key is depressed.

The current passes tothe station Y by way ol' relays R R2,and at stationY it flows around the armature A of relay R3 and then to earth. Relay R3is polarized, N S beinga permanent magnet. The armature A will thereforemove up and down on its center b, the polarity of the first currentgoverning the 'direction of the first movement. Attached to the armatureA are two arms fr Qc'. Their normal position is between the teeth of theescapement-wheels E E'. These wheels are constructed in a peculiar way,as is better shown in Fig. 3. The ends of the arms xx rest between thetwo wheels E E'. The rst downward movement of either arm engages with atooth of wheel E'. If the polarity of the rst impulse from station X isa positive one, the

sh uttle-arm M moves to the right and the arm moves downward. In doingso it strikes the tooth of wheel E and turns the wheels and the shaft S,which is fastened thereto, the distance-of one tooth to the left. Thenext impulse, which will be a negative one, will move the' arm x upward,which will strike the tooth above it and move the shaft the distance ofone more tooth to the left, and so on. In the meantime the arm has beenmoving in the opposite direct-ion to the arm and has en countered noteeth. Its rst movement was upward and the next downward, and so on; butthe wheels are so formed that the arm moves in open spaces during thesucceeding alternations of current.

If the first current from station X be negative, there will be a reverseeffect. The end of the armature A to which the arm is fastened will bemoved first. This will move the arm Q0' downward rst, and it will engagewith the tooth below and drive the wheels and the shaft S the distanceof one tooth to the right. The next impulse will send the arm upward,and it will strike another tooth and drive the shaft the distance of onemore tooth to the right, and so on. In the meantime the arm has beenplaying between blank spaces. By this arrangement of the teeth on thewheels the shaft will be driven in opposite directions by the two armsof the rela-y R3. The wheels E E can be reversed in position,if desired,and the first upward movement of either arm may then be made to governthe direction of the shafts mot-ion. The first impulse from thecommutator O at station X maybe negative instead of positive byconnecting the negative dyn amo to the first segment instead of thepositive one.

Attached to the shaft S is the contact-arm M'. This moves with the shaftand moves over the segments of the cominutator C, to each segment ofwhich is connected a solenoid O, having a movable core o and a fixedcore 0'. When the solenoid is energized by the local battery L, it pullsthe movable core 0 down, and with it the keyP, to which the movable coreis attached. This of course has the same effect as striking the key withthe finger, and it prints the letter on the paper of the machine in thesame way. In order to release the key aft-er the letter has been printedon the receiving-machine at station Y, the electromagnet M2 is broughtinto action. When the keyP has been pulled down by the solenoid O, thehammer is driven for- IOO IIO

ward in order to print the letter on the paper.

As it moves forward it closes the circuit of the electromagnet M2 atcontacts c c', the former being fixed and the latter attached to thehammer.

The armature A2 of the electromagnet M2 is fastened to the shaft S andturns with it, and when it turns it moves out of its normal positionbetween the poles of the magnet M2. X'Vhen the circuit of this magnet isclosed, the magnetism generated at i ts poles will act upon thearma-ture A2 with such a force that it will pull it around, so that itwill come back to its normal position between the poles of the magnetand be held there. The shaft S will be turned at the same time, and itscontact-arm M will be brought to the segment m. This contact c2 isattached to the hammer.

mutator C,to which the solenoid is connected, and in moving o thecircuit of the solenoid is broken. The movable core 0 is no longerattractedinto the solenoid and it flies up, allowing the key P to takeits normal position.

It will be apparent from the foregoing description that at the same timethat the shuttle or contact arm M of the transmitting-machine at stationX is returned to the unisonpoint m by the mechanical devices of theHammond machine the contact-arm M of the receiving-machine at station Yis brought to its corresponding unison-point on by the armature A2 ofthe magnet M2, as j ust described.

.Vhen the hammer H of the transmittingmachine at station X fliesforward, it opens the line at contacts c2 c3. This is done for thepurpose of breaking the circuit, so that the armature A of the relayRgof the receiving-machine at station Y will come to rest between thetwo wheels E E and allow them to be turned by the arma-ture A2 of themagnet M2. lf the line were not opened in that way, the arms of thearmature A would be held up or down into a tooth of the wheels E or E',and the shaft S would be prevented from turning freely. The contact csis fixed and After the letter has been struck ou the transmitwting-machine at station X the key is released by the finger and theshuttle-arm M falls back to its original position. In doing so it makescontact with the commutator C, and were the line closed it would sendcurrents to station Y, thereby driving the escapementwheels of thereceivinginstru ment farther on but as the line is open at the hammerthese currents are not sent to station Y. The hammer H closes thecircuit when it flies back. It returns to its normal position as soon asthe sluittle-arm M does, and therefore the line is closed in time forthe next letter to b'e printed.

Either machine can be used for ofce-work' by simply turning thetwo-point switch .S to the right. This leaves it in a position forreceiv ing, as is shown at station Y in Fig. l.

Fig. 2 illustrates the paper-carriage feed, release, and return.

S2 is a shaft,on the back end of which is a collar, with a slot turnedin it all the way around in order to allow the two prongs of a fork toclutch it, so that it can slide the shaft S2 back and forth and yetallow it to be turned by the spring s. The fork is securely attached tothe rod R4, which extends under the machine and is connected to thecrank R, attached to the key K. Then the key is depressed at thetransmitti11g-machine at station X or pulled down by the electricaldevices of the receiving-machinev at station Y, the fork moves the shaftS2. Upon this shaft is securely fastened the ratchet O2, in the teeth ofwhich the pawl n2 engages to keep the spring s' from unwinding. A drumD2 is loose upon the shaft S2, and the ratchet Ois secured to this drum.The pawl n3 only engages with the teeth of the ratchet when the shaftand drum are pushed o ut. The drum D2 is free to turn on the shaft S2,but moves with it when it is pushed out. Firmly secured to ,the otherend of the drum D2 is the gear-wheel G2, upon which the teeth of thecarriage-rack K ride. They also ride upon the gear-wheel G3,which issleeved on the shaft S2, so as not to move with it.

The spring s is fastened on its end to the shaft S2 and at the other endto the drum D2. It has been wound up to the necessary tension, and inthe tendency to unwind gives the drum D2 a direction of rotation. Thisforces the carriage-rack and carriage in the same direction, and upon astroke of the type-writer key it moves one definite distance. Thecarriage does not move until a key is struck, being held by a pawlagainst a tooth of the ratchet-wheel O', and as soon as akey is struckthe pawl is moved away one tooth and then restored, moving` one toothahead upon the pressure of the succeeding key. This is a feature of themechanical type-writer and is not claimed as a part of our invention.

lVhen the carriage is to be returned, the key K is depressed by theoperator at station X and pulled down bythe electrical devices atstation Y. This pushes the rod R4 back and with it the shaft S2. Thedrum D2 and gear-wheel G2 are thereby pulled completely out from underthe rack K. The rack then rests upon the gear-wheel G3 alone, the springs2 of which has been wound up by the forward movement of thecarriage-rack and has acquired sufficient tension to turn the gearwheelG3 in the opposite direction to that in which the spring s' turned thegear-wheel G2. As the rack K now rests upon the gear-wheel G3 only andas this gear is given a tendency to rotate by its spring s2, the rack isforced along with it until it is returned to the starting-poiht. lVhenthis point is reached, the key is released, the shaft S2 is restored,and the gear-wheel S2 slips under the rack and is ready to move itforward again. The spring s' is very much more powerful than the springS2, which is just strong enough to return the carriage, the latter beingvery light and riding over rollers. Vhen the drum is pulled out fromunder the rack K, the pawl n3 engages with a tooth of the ratchet O3,preventing the spring s from unwinding. The pawl n2 is always engaged ina tooth of the ratchet O2.

The springs' is wound to the requisite tension to force thecarriage-rack. K along one.

step upon the pressure of each type-writer key. As the spring unwinds atthat rate, it would very soon become run down. Thisis overcome by meansof the electromagnet M4. After each key is struck the circuit of theelectromagnet is closed at Z or any other suitable place and itsarmature A4 pulled upward. The 'end a4 of the armature fits into a toothof the ratchet O2, forcing it around and winding the spring s one step.This happens with every letter, and-the spring s is thus kept at itsinitial tension.

IOO

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Instead of the armature of the electromagnet winding up the spring s/ itcan be replaced by a lever attached to any of the movable arms,suflicient pressure being given the keys to move the lever with forceenough to drive the ratchet O2 one tooth for every tooth itV loosens.The lever in that case would take the position now occupied by thearmature of the magnet M4.

In Fig. 4 we have shown one method of holding down and locking thecapital or iigure key of the receiving-machine and also the method ofreleasing it. W'hen the capitalkey of the transmitting-machine atstation X is depressed, it sends to the line a definite number ofpulsations, according to its position. In this case it is the first key.Therefore it sends 'one impulse to the line. This moves this contact-armM of the receivingmachine at station Y onto the rst contact o' of thecomm utator C'. The solenoid O2 is thereby energized, and it pulls downits movable core o2 and with it the capital or figure key K2. At thesame time the stationary core O3 of the solenoid becomes a magnet andattracts the armature A5 to it. As the armature moves toward the-magnetit strikes the rod R6 and forces its upper end against the notch l inthe latch L2,which is pivoted at Z2, and drives it forward, when itengages with the collar C2 on the movable core 02 and holds it down.Just at this time the armature A5 has closed the circuit of theelectromagnet M2 at y. The magnet attracts its armature A2 and restoresthe contact-arm M to the position of rest on the segment m'. The circuitof the solenoid O2is thereby broken and the armature A5 falls back toits original position. The movable core 02 will tend to rise, but willbe prevented from doing so by the latch L2, which holds down its collarC2.

Vhen the gure or capital key is released by the operator at station X,one impulse will be sent to the line, the contact-arm M of thereceiving-machine at station Y will be moved to the segment c', and thecircuit of the solenoid O2 will again be closed. The solenoid will beenergized and will attract the armature A5, as before described. Thismotion of the armature will operate the rod R6 and the upper end of therod will engage with the notch l2 of Athe latch L2, which was drivenforward, as

above described. The shape of the latch is such that the engagement ofthe rod R6 with the latch Z2 will drive it back to the position shown inFig. 4. The collar 2 will then be free from the latch and the movablecore o2 will rise when the armature A2 of the segment M2 has broken thecircuit of the solenoid O2, as before described.

The operation of our invention is as follows: The operator at station Xdepresses the key P. This may be the fifteenth or any other key, andassuming that it is the fteenth key the shuttie-arm M will be movedaround to the fifteenth rod R, which has been raised, and will stopthere, as before described. In moving over to the fifteenth rodfthe armM passes over fourteen contacts of the commutator C, one for each key,and comes to rest on the fifteenth. This sends fifteen current-s to theline and moves the armature A' of relayR3 of thereceivinginstrumentatstationYfifteen times. The armature A by means ofits arms moves the shaft S' and the contact-arm h in the manner alreadydescribed to the fifteenth segment of the commutator O', where thecontact-arm comes to rest. The solenoid O is thereby energized and pullsdown the key P, which corresponds to the one depressed by the operatorat station X. Then the hammer H of the receiving-machine at station Yiies forward, it closes the circuit of the magnet M2, which restores thecontact-arm M to the unison-point on the segment m by means ot' itsarmature A2, as has been also described. At the same time theshuttle-arm M of the transmitting mechanism at station X is returned tothe unison-point on the Segment m mechanically on the release of the keyP. The two arms M M' move in step with each other and each is restoredto its original position or unisonpoint after the printing of everyletter, and should one letter for any reason be misprinted at station Ythe next one will be correctly printed, as the con tact-arm M will havebeen restored to the unison-point after the misprinting of the letterand will therefore be in a position to be correctly operated by thedepression of the next key. The contactarm M' of the receiving-machineat station Y moves so quickly over the contacts of the commutator C thatthe solenoids are not energized until it comes to rest.

If the line-wire should open or ground or get crossed with another, sothat station Y will not get the currents from station X, thetransmitting-machine at station X is locked automatically, so that itcannot be operated. This is accomplished by means of the relays R R2.The currents from the transmittingmachine at station X in passing to thereceiving-machine at station Y ow through these relays. The spring r' ofrelay R' is sufticiently strong to overcome the magnetism of its core,and it therefore keeps the armature up at the top stop. The spring ofrelay R2, however, is weaker, and the currents iowing thro ugh thatrelay pull the armature down and keep it on the lower stop. Theelectromagnet M2 is therefore kept on open circuit. If the line-circuitshould open, the current will not circulate around the relay R2, and thespring,having no magnetism to overcome,will then pull the armature tothe upper. contact. In doing this it will close the circuit of theelectromagnet M3, which pulls its armature A3 forward and directly underthe pawl or', holding it firmly, and thereby preventing the ratchet Ofrom moving and locking the machine. Should the line become grounded orcrossed with another wire, the excess of current flowing around thecores of the relay R will create a greater amount of magnetism creasecurrents.

in its cores, and this increase will overcome the force of the springfr' and pull the armature down to the lower contact, closing the circuitof the magnet M3 and locking the typewriter. The armature A3 of themagnet M3, which is upon open circuit, is 'free from the paWl n When theline-Wire is in Working condition, and it does not interfere with theoperation of vthe machine. This magnet, with its armature, can be placedat any other part of the machine Where it Will prevent its operation byholding the moving parts of the machine iirmly. 1

W'hen the shuttle-arm M of the transmitting-machine at station X isresting in its normal position on the segment m, there is no currentiiowing to the line. This would cause the relay R2 to open and lock themachine but for the local circuit which is kept closed through itscoils. This circuit can be traced from the shuttle-arm, Wire lV, localbattery L', around relay R2, to the shuttle-arm by Wire l l. W'hen theshuttle-arm moves off this contact, it throws the relay R2 into theline-circuit.

Any type-Writer operated upon a. mechanical principle similar to that ofthe Hammond machine can be equipped with similar eleotrical apparatus,and any printing-machine that has a type shuttle,77 type wheel,type-cylinder, or which has all its letters on one ortwo pieces ofmechanism which turn or move one definite distance farther with thedepression of each succeeding key, can be operated upon the electricalprinciple herein described. This can be done by alternating make andbreak or increaseand de- Upon the printing of each letter the typeWheels or cylinders are mechanically brought to their original position.This principle can be adapted to any of the type-bar machines should anypiece of their mechanism move one definite distance farther with thedepression of each succeeding key, or such a piece of mechanism could beattached to them.

Having thus fully described ourinvention, we claim and desire to secureby Letters Patent of the United Statesl. The combination in asystem ofelectrically-connected printing-machines of a mechanical type-Writercontaining a mechanism which is moved from a determinate posi-tion onedefinite distance farther by the depression of each succeeding k'ey ofthe machine, and which is restored to a determinate position upon therelease of the key, of a series of contacts over and upon Which themechanism passes, a source of electricity and a line-Wire, substantiallyas described.

The combination in a system of electrically-connected printing-machinesof a mechanical type-Writer containing a mechanism which is moved from adeterminate position one deiinite distance farther by the depression ofeach succeeding key of the machine, and which is restored to adeterminate position upon the release of the key, acommutator over andin contact with which the movable mechanism passes, a source ofelectricity and a line-Wire, substantially as described.

3. The combination'in a system of electrically-connectedprinting-machines of a mechanical type-Writer containing a mechanismwhich is moved from a determinate position one definite distance fartherby the depression of each succeeding key of the machine, and which isrestored to a determinate position upon the release of the key, a seriesof contacts by means of which pulsations of electricity are sent to theline and receiving instrument by the movement of the movable mechanism,and means for preventing further operation of the receiving instrumentwhen the movable mechanism is being restored to its determinateposition, as and for the purposes described.

Il. The combination in a system of electrically-connectedprinting-machines of a source of electricity, a transmitting mechanismhaving a commutator and a contact-arm adapted to be moved one definitedistance farther by the depression of each succeeding key of the machineand brought to its initial position on the release of the key, areceiving mechanism having a commutator and a contact-arm adapted to bemoved by one or more electromagnets in unison with the arm of thetransmitting-machine and mechanism to automatically bring thecontact-arm to its initial -position in4 unison with the transmittingcontact-arm after the printing of each letter, as and for the purposesdescribed.

5. In a system of communication by means of printing-machines connectedby a single line-Wire, a receiving printing-machine, a contact-arm, oneor more toothed Wheels to move the contact-arm, one or moreelectromagnets to operate the wheels and mechanism to automaticallyrestore the contact-arm to its initial position instantly upon theprinting of each letter'and before the nextis struck, in combinationwith a transmitting-machine, a commutator and a source of electricity, acontact-arm adapted to be moved one definite distance farther bythedepression of each succeeding keyof the machine and restored to itsinitial position upon the release of the key, both contact-arms movingin unison, substantially as described.

In a system of communication by means of printing-machines connected bya single line-Wire, a receiving printing-machine, a contact-arm, one ormore toothed wheels to move the contact-arm, one or more electromagnetsto operate the Wheels and mechan- IOO IIO

ism to automatically restore the contact-arm to its initial positioninstantly upon the printing of each letter and before the next letter isstruck, as and for the purposes described.

7. In a system of communication by means of printing-machines connectedby a single line-Wire, a receiving printing-machine having a commutator,a contact-arm adapted to be moved a step farther by each succeedingimpulse from the transmit-ter and to be automatically brought to itsinitial position by means independent of the transmitter instantly afterthe printing of each character and before the next letter is struck, asand for the purposes described.

S. In a system of communication by printing-machines connected by one ormore wires, a receiving-machine, a contact mechanism adapted to be movedby one or more toothed Wheels, one or more electromagnets to operate theWheels and means for automatically bringing the contact mechanism to adeterminate position by the action of the printing of each character, asand for the purposes described.

S). The combination in a system of electrically-connectedprinting-machines of a papercarriage having a rack, a spring for moving`the -carriage one step with the depression of each key, a drum, a gear,means for Winding the spring with each step it loses, mechanism formoving the drum from under the rack, a ratchet-Wheel and pawl to preventunwinding of the spring and a spring for returning the carriage Wound bythe forward movement thereof, substantially as and for the purposesdescribed.

1'0. The combination in a system of electrically-connectedprinting-machines of the paper-carriage, the shaft S2, the rod R4, thedrum D2, the spring s', the ratchet O2, the

spring s2, the gear G3, the electromagnet M4 with its armature A4 andthe pawls n2, n3, substantially as described.

ll. In a system of communication by means of printing-machines connectedby a single line-Wire, a receiving printing-machine, two wheels eachwith oppositelyinclined teeth tator C', the contact-arm M', solenoidselectrically connected to the segments of the conimutator, theelectromagnet M2 With its armature A2, as and for the purposesdescribed.

13. In a system of communication by means of printing-machines connectedby a single line-Wire, a transmitting-machine, a contactarm connected tothe line-wire and adapted to be moved in opposite directions from agiven position one definite distance farther by the depression of eachsucceeding key of the machine, a commutator over which the contactarmmoves, opposite electrical polarities connected to the first and to thesucceeding segments of the commutator on each side of a given positionand mechanism to automatically restore the contact-arm tothe givenposition upon the release of the key, as and for the purposes described.

14. The combination in a system of electrically-connectedprinting-machines of the capital-key K2, the solenoid O2 having themovable core o2, the armature A?, the rod R6, the latch L2 and thecollar C2, as and for the purposes described.

' CHRISTOPHER A. SHEA.

JOHN J. OLALOR. In presence of J. M. DoLAN, JAMES A. LOWELL.

